In case anyone is interested in the architecture behind this, job-scheduling, etc., I'd happily write it up in a blog post or something. It took a few releases/products to put together a nice, reliable and slim model that withstands HN mayhem easily (I run this on a $15-20/month server without that machine even showing a hint of sweat). I use this model/architecture for all prototypes I build and it allows to release/modify/adapt quickly once it goes live.

EDIT: Also, Stripe is just awesome. It just works, so, well. I even made $20 today, so cool, I'll make sure to re-invest this in one of the next Show HNs! Thanks guys!